California Nature


San Andreas Fault

For 38 million Californians, the evidence is in plain view that San Andreas fault can't be ignored. The San Andreas Fault runs from east of San Diego northward. San Andreas Fault system runs over 650 miles through 16 California counties. It passes east of Los Angeles, continues northward east of Monterey, then passes through the towns of San Juan Bautista and Hollister. It continues northward just west of San Jose, up the San Francisco Peninsula, continues northward and eventually turns west into the Pacific Ocean south of Eureka.

It has released enormous energy in countless earthquakes ranging in magnitude from tremors to cataclysmic upheavals that have ruptured the Earth's surface. In 1906 it destroyed many of San Francisco's buildings in one of the largest earthquakes in US history.

The slow, jerky motion of the San Andreas Fault along Cienega Road south of Hollister split the aging cellar of the DeRose Vineyards (formerly the Almaden Winery). A giant crack runs down the middle of the building and inch by inch, year by year, the fault is shearing the buildings and its foundation. Inside the wine cellar is a bronze plaque proclaiming the San Andreas Fault as a Registered Natural Landmark.

Now the subject of a field guide for travelers, astronomer and planetary scientist David Lynch, PhD, brings its mighty strength to life in a book that takes you to actual spots where you can see how the earth is affected by its force.

Field Guide to San Andreas Fault - Book Release about Earthquakes Field Guide to the San Andreas Fault by David K. Lynch, PhD, Thule Scientific, P.O. Box 953, Topanga, CA 90290. Tel: (310) 455-3335. Email:

The San Andreas Fault Exhibit & El Camino Real Earthquake Walk

In Celebration of the
U.S. Geological Survey's Centennial
1879 - 1979
Dedicated July 4, 1979

In Cooperation With Old Mission San Juan Bautista-Diocese of Monterey, U.S. Geological Survey-Department of the Interior, California State Historical Park-San Juan Bautista
and the Citizens of San Juan Bautista, California

Erected 1979 by Mission of San Juan Bautista, U.S. Geological Survey, San Juan Bautista State Historical Park and Citizens of San Juan Bautista.

Marker is in San Juan Bautista, California, in San Benito County. Click for map. Marker is located on the grounds of the Mission San Juan Bautista and the San Juan Bautista State Historical Park. Marker is at or near this postal address: 300 Second Street, San Juan Bautista CA 95045, United States of America.

Earthquake Q & A:

"Does earthquake weather exist?" Californians call it "shake and bake" when an earthquake occurs during a heat spell. In the authoritative guide based on science and facts, you'll find answers to some of the most common questions about earthquakes.

Field Guide to the San Andreas Fault order information- The book is spiral bound and lays flat for easy reading in the car. It is also available on CD so that people can print out just the route they are taking. Contact: David K. Lynch, Thule Scientific, P.O. Box 953, Topanga, CA 90290. Email:

When it comes to revealing a fault, few places in the world can compare to the Carrizo Plain National Monument. Located in central California, the area is home to part of the San Andreas Fault and contains some astonishing landforms. The fault is the sliding boundary separating the North American Plate and the Pacific Plate. Here a particularly dramatic part of the fault, called the Elkhorn Scarp, can be seen. The fault lies along the obvious top-to-bottom trough and crossing it are many small erosional valleys. Together they form the Dragon's Back, a long linear ridge with many regularly-spaced serrations. The Elkhorn Scarp is part of a pressure ridge, a region that has been uplifted as the two plates are forced together. While most of the motion is transverse and the plates grind horizontally past each other, a small compressional component has raised the Elkhorn Scarp. The picture was taken from an altitude of about 5,500 feet (1,677 m) and is about a mile (1.6 km) from left edge to right edge at mid-picture.


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